That plot is from a blog of a Bitcoin Cash (BCH) supporter. He talks about various sophisticated statistical concepts, without showing the math, and even uses "miners will blacklist the IP address of selfish miners" as an argument. I wouldn't assign much credibility to that analysis, though it has some amount of truth, it is not a full, unbiased analysis of the situation. Even if his model is correct, selfish mining isn't the only attack I'm concerned about, as I have mentioned in previous posts of this thread.
I see, thanks. No I didn't realize there was any relevance to BCH vs. BTC here. My point is just that there is no "selfish miner attack", for any coin, any more than a karate expert need concern himself with a "hit yourself in the eye" attack by his opponent. Withholding blocks won't have any positive effect for a miner unless the miner is engaging in some 51 percent attack.